CRIME author Bernard O’Mahoney today reveals how his penpal letters helped snare some of the North’s most notorious child killers.

The 52-year-old used a host of pseudonyms to befriend vile paedophiles who had abducted and murdered innocent children.

And after gaining their trust and extracting confessions, his evidence helped solve some of the most infamous murders the region has ever seen.

Among those to confess was Shaun Armstrong, who was jailed for life for the brutal murder of three-year-old Rosie Palmer. Her battered and sexually-abused body was discovered in a bin liner in his home.

He protested his innocence to police but confessed to the crime in letters he wrote to author Bernard, who posed as a woman to gain Armstrong’s trust.

Armstrong was jailed in 1995 following an 11th-hour confession after police were given the letters. He had abducted Rosie when she went to buy an ice lolly at a shop near her home in Henrietta Street, Hartlepool. In 2000 Armstrong launched a bid for £15,000 in compensation, claiming breach of confidence, but Bernard eventually fought off the legal action.

But now, in a new book called Flowers in God’s Garden, Bernard has revealed how he helped bring three child killers to justice.

And letters from child killers are also published for the first time in which the likes of Shaun Armstrong and Richard Blenkey, who murdered seven-year-old Paul Pearson in August 1991.

Bernard, who lives in Gateshead, said: “I wrote letters to the Yorkshire Ripper and he answered every question I asked. In the same week Richard Blenkey murdered Paul Pearson and I just wondered if he would be so open.

“I’ve been to prison myself for my sins so I know that when someone contacts you it can be like a shining beacon of hope.

“He invited me to come see him and so I went to visit him. Over the course of 12 months he detailed the murders but always said it was a third person.

“Then, a week before the trial, I just put it to him that he had carried out the murder and he admitted it.”

Blenkey was 32 when he strangled Paul with red twine in a chicken hut at Hazel Grove allotments in Saltburn.

The little boy’s body was discovered in an overgrown ravine on Thursday, August 15, 1991. He had died from strangulation and had been sexually assaulted.

Despite this, Blenkey was never charged with the sexual offences and abduction.

And the fact his conviction predates the introduction of the sex offenders’ register means he is exempt from signing it.

Paul’s family launched a campaign to introduce Paul’s Law which would ensure offenders are charged with all the crimes they are suspected to have committed – not just the most serious.

Bernard said: “The book has been criticised because people have said that ‘it gives paedophiles a platform’.